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Thank you We sneak and here's your smoke du jour

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brought to you by heavy metal Mercury is a heavy

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metal and we were heavy metal to uh we're about

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six months aren't following information may be useful Density of

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iron is seven point eight eight grand person amir cubed

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dancey of mercury is removed Three agency of water is

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one all right Well as the on ly metal that

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is liquid at room temperature mercury is a curious metal

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If we placed one cubic centimeter iron cube into a

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cup of water it would quickly sink However if we

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place that same iron cube into a cup of mercury

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it would float approximately what fraction of the iron cube

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is submerged in the liquid mercury And here the potential

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answer All right Well here we go Mercury is a

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pretty cool medal It's the only metal that's liquid at

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room temperature it's also poisonous mercury is very dance which

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means that even heavy things will float in it when

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something or someone floats The downward force of gravity is

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counterbalanced by the upward force of the material It's A

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floating in that upward force is called buoyancy The downward

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wait is expressed as density times volume times gravity where

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volume equals the total volume of the floating object Well

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the buoyant forces expresses the density of the fluid times

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the volume of the submerged portion of the floating object

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times gravity The buoyant force also equals the weight of

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the displaced fluid Well for this question we need to

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figure out how much of the little iron block is

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submerged in the mercury All right well now we could

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probably think a ruler in measure everything and calculated percentage

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but well it sounds like a lot of work Luckily

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for us there's an easier way in any buoyant system

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The fraction of the object that submerged in a fluid

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can be figured as a ratio of the densities of

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the object and the fur fluid The ratio of the

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volume of the submerged portion of the object to its

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total volume is equal to the ratio of the density

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of the floating object to the density of the fluid

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it's floating in it's a good thing we were given

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the densities than material when we started this whole thing

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Otherwise we'd be a finger deep in mercury and did

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we mention the whole poison thing Yeah well the density

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of iron is seven point eight eight grams per cubic

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centimeter and the density of mercury is thirteen point three

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five grams per cubic centimeter When we plugged those numbers

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in like this we find that fifty eight percent of

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the cube is submerged and we're looking for an approximate

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here So answer c is the right choice And as

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with a lot of things in physics there's more than

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one way to look at buoyancy It just depends on

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what we're trying to figure out and sometimes figuring ourselves

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out involves leopard print tights and a lot of makeup 00:02:51.015 --> [endTime] Yeah

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